Self-cooled transformer.



J. J. MULLEN. SELF GOOLED TRANSFORMER.

APPLICATION FILED AUG. 21, 1911.

71 039 577 Patented Sept. 24, 1912.

UNITED STATES PATENT OFFICE.

JAMES J. MULLEN, OF ST. LOUIS, MISSOURI, ASSIGNOR TO MOLONEY ELECTRIC COM- PANY, OF ST. LOUIS, MISSOURI, A CORPORATION OF MISSOURI.

SELF-COOLED TRANSFORMER.

To all whom it may concern:

Be it known that I, JAMEs J. MULLEN, a citizen of the United States, residing at St. Louis, Missouri, have invented a certain new and useful Improvement in Self-Cooled I Transformers, of which the following is a. full, clear, and exact description, such as will enable others skilled in the art to which ranged that they are surrounded on all sides it ap ertains to make and use the same.

This invention relates to self-cooled transformers, and particularly to the tanks or casings of such transformers which contain the liquid in which the transformer is submerged.

The main object of my invention is to provide a self-cooled transformer which is so designed that the temperature rise is, lower and more uniform than in the various types of self-cooled transformers heretofore and communicatmg with openings therein.

used.

Another object is to provide an ineX-* percentage of heat-radiating surface than the tanks heretofore used for incasing selfcooled transformers.

Other objects and desirable features of my invention will be hereinafter pointed out.

Figure 1 of the-drawings is a side elevational view, artly broken away, of a selfcooled trans ormer constructed in accordance with my invention; Fig. 2 is a similar view of the casing taken at approximately right angles to Fig. 1; Fig. 3 is a top plan view of the casing with the removable top broken away so as to more clearly illustrate the arrangement of the air conduits; Fig. t is a detail view illustrating a slight modification of my invention; and Fig. 5 is a detail view illustrating still another slight modification of my invention.

Referring to Figs. 1 to 3, inclusive, which illustrate the preferred form of my invention, A designates a transformer of any preferred type or design that'is arranged inside of a casing or tank B which contains a liquid, preferably oil, in which the transformer is submerged. The casing it may be formedeither from sheet metai metal but I prefer to form it from cast metal and'cast the bottom 1 integral with the side walls 2. The top the casing is preferably removable and is retained in position by suitable fastening devices such, for example, as screws & which Seriai No. 645,051.

pass through ears 5 on the top 3 and project into screw-threaded openings in cooperating ears 6 on the sides of the casing.

Air conduits C are arranged inside of the casin so as to absorb heat from the liquid and thus give a relatively great heat-radiating surface in addition to the side walls of the casing. Said conduits are so arby the liquid in the casing and they are so constructed that currents of air will circulate through same continuously. In the embodiment of my invention shown in Figs. 1 to 3, the conduits C are open at both ends and are arranged vertically inside of'the casing B a slight distance from the inner surface of the casing, the ends of said conduits projecting through openings in the casing or terminating inside of the casing I prefer to form the conduits C from pieces of pipe which are arranged in the mold in which the casing is formed prior to the operation of pouring the molten metal into the mold, thereby producing a structure in which the conduits are practically cast integral with the casing. The lower ends of the conduits project through the bottom 1 of the casing, and the upper ends of said conduits branch 'outwardly, as shown in Figs. 1 to 3, and project through theside walls of the casing adjacent the upper edges of same. It is immaterial, however. so far as my invention is concerned, whether the conduits are connected to the casing in the manner above-described or in other ways as my broad idea consists in )roviding the easing of a self-cooled transformer with openended air conduits that are submerged in or surrounded by the liquid in the casing that receives the heat from the transformer.

Instead of having the upper ends of the conduits C branch laterally and project iii the support on which the casing rests to permit air to travel under the flange 7 on the lower end of the casing and pass upwardly through the conduits C, as indicated by the arrows in Fig. 1. One means that may be used for this purpose consists of depending flanges 8 on the bottom of the casing which act as supporting legs for the casing and also as skid-rails that permit the casing to be dragged or pushed easily over the support on which it rests.

The heat which radiates from the conduits C and passes upwardly through same is sutiicient to induce currents of air upwardly through said conduits, but, if desired, the casing can be provided at its lower end with an air chamber 9, as shown in Fig. 5, that comnninicates with the lower ends of the conduits C and to which air is supplied by any suitable means, not shown, so as to torce currents of air upwardly through the conduits C. instead of forcing air up through the conduits C a suction-producing device, not shown, could be connected to the air chamber 9 so as to cause air to travel downwardly through the conduits C.

The temperature rise of a selfcooled transformer of the constructioi'i above-described is lower and more uniform than in the sel'hcooled transformers heretofore'in use because the casing of the transformer is provided with. a heat-radiating surface of relatively great area consisting of the side walls of the casing and conduits C that are completely surrounded by the oilin the easing and which are so arranged that currents of air will travel through same continuously and thus carry away the heat which radiates from said conduits. Furthermore, a transformer casing of the construction abovedescrihed is inexpensive to manufacture, it is symmetrical and presents a neat and ornamental appearance, and it is compact. I

aving thus described my invention, what 1: claimas new and desire to secure by Let- Loa er jacent the side walls of same and having their upper and lower ends communicating with the atmosphere so that currents of air will travel through said conduits.

2. A self-cooled transformer consisting of a casing that adapted to contain a liquid, a transformer arranged inside of said casing, vertically disposed air conduits arranged inside of said casing adjacent the side walls of same and having their upper and lower ends communicating with the ate mosphere so that currents of air will travel through said conduits, and means for holding the bottom of the casing for enough away from the support on which the casing rests to permit air to enter the lower ends of said conduits.

3. A casing or tank for seliicooled trans formers consisting of a cast metal shell whose bottom and side walls are integrally connected together, vertically disposed air conduits a ranged inside of said shell and integrally connected to the bottom of the Shell, the upper ends of said conduits communicating with the atmosphere so as to permit currents of air to circulate through said conduits, and a removable top or cover for said shell.

4. A casing or tank for self-cooled transformers consisting oi a cast metal siell whose bottom and side walls are integrally connected together, vertically disposed air conduits arranged inside of said shell and integrally connected to the bottom of the shell, the upper ends of said conduits communicating with the atmosphere so as to permit currents of air to circulate through said conduits, a removable top or cover for said shell, and depending flanges on the bottom of the shell which hold same a suiilcient distance from the support on which the cas Janus l Witnesses Warts la. Cnnnon, GEO, R, Larson, 

